I prefer a spur hammer over an un-spurred hammer. Took my 4516 to my local gunsmith (30 miles distance) and left the 4516, replacement spur hammer and struct. When I picked the 4516 up after replacement and went to the range to test fire. Out of a magazine of .45acp FMJ ammo the 4516 would double fire at least once. Returned the pistol to the gunsmith a second time. Picked up the "Repaired" weapon and went to the range to test fire. Now the pistol was D/A only !!. Returned the 4516 a third time and request that the original parts be installed. Gunsmith requested to try repairing it again. Now I am waiting for the gunsmith call and range test it a third time.